TS87C54X2-VCB Atmel, TS87C54X2-VCB Datasheet - Page 21

• Manufacturer Part Number: TS87C54X2-VCB
• Description: IC MCU 8BIT 16K OTP 40MHZ 44PLCC
• Manufacturer: Atmel
• Series: 87Cr

Specifications of TS87C54X2-VCB

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40/30MHz
• Connectivity: UART/USART
• Peripherals: POR, WDT
• Number Of I /o: 32
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: OTP
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-PLCC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

9.1.3
9.1.4
4431E–8051–04/06
Broadcast Address
Reset Addresses
The following is an example of how to use given addresses to address different slaves:
Slave A:
Slave B:
Slave C:
The SADEN byte is selected so that each slave may be addressed separately.
For slave A, bit 0 (the LSB) is a don’t-care bit; for slaves B and C, bit 0 is a 1. To communicate
with slave A only, the master must send an address where bit 0 is clear (e.g. 1111 0000b).
For slave A, bit 1 is a 1; for slaves B and C, bit 1 is a don’t care bit. To communicate with slaves
B and C, but not slave A, the master must send an address with bits 0 and 1 both set (e.g. 1111
0011b).
To communicate with slaves A, B and C, the master must send an address with bit 0 set, bit 1
clear, and bit 2 clear (e.g. 1111 0001b).
A broadcast address is formed from the logical OR of the SADDR and SADEN registers with
zeros defined as don’t-care bits, e.g.:
Broadcast =SADDR OR SADEN
The use of don’t-care bits provides flexibility in defining the broadcast address, however in most
applications, a broadcast address is FFh. The following is an example of using broadcast
addresses:
Slave A:
Slave B:
Slave C:
For slaves A and B, bit 2 is a don’t care bit; for slave C, bit 2 is set. To communicate with all of
the slaves, the master must send an address FFh. To communicate with slaves A and B, but not
slave C, the master can send and address FBh.
On reset, the SADDR and SADEN registers are initialized to 00h, i.e. the given and broadcast
addresses are XXXX XXXXb (all don’t-care bits). This ensures that the serial port will reply to any
address, and so, that it is backwards compatible with the 80C51 microcontrollers that do not
support automatic address recognition.
SADDR
SADEN
Given
SADDR
SADEN
Given
SADDR
SADEN
Given
SADDR
SADEN
SADDR
SADEN
Broadcast 1111 1X11b,
SADDR
SADEN
Broadcast 1111 1X11B,
SADDR=
SADEN
Broadcast 1111 1111b
1111 0001b
1111 1010b
1111 0X0Xb
1111 0011b
1111 1001b
1111 0XX1b
1111 0010b
1111 1101b
1111 00X1b
1111 0001b
1111 1010b
1111 0011b
1111 1001b
1111 0010b
1111 1101b
0101 0110b
1111 1100b
1111 111Xb
AT/TS8xC54/8X2
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